Got Ram - but now what do I get?

[caissiel]

I would not worry a bit.
I towed a 5600 lbs RV with a 2.9L Ranger for 3 years and it had 100k when I bought and got $1500 less then I bought it for when I traded it in with 200k.
My friend towed a 6500 lbs RV with his Dakota 3.9L with 60k for 3 years also with no issues.

It's how you drive that is important, not what you drive.

[CJBROWN]

Originally Posted by gggplaya

For 2003, looks like a 3.92 axle ratio was an option. I'd probably get that installed if you plan on doing extensive towing. Here's the reference: 2002 Dodge Ram 1500, 2500, and 3500 specifications

The best place is probably to take it down to a 4x4 specialty offroad shop or driveline shop that does these types of replacements often. It takes some shimming and spacing to get it just right. In total with parts it'll probably cost about $1000 for a 4wd. If you take it to the dealer, they'll charge you about $1500 for both sets of ring and pinions alone, tack a few hours of labor on top of that.

This is actually a good plan. Lower gearing makes a huge difference in how they pull.

It didn't look like a 4x4, so just one diff. Another alternative may be a complete axle from a wrecking yard. Might get one to swap out for a few hundred bucks. BTW, the differential needs an oil change for towing too.

I did a gear change on a jeep to run big tires. Had a Dana 44 built for the rear with a locker, got a D-30 front take-out from a 4cyl since they had lower gearing. So 4:11's front and back. I had less than a grand in it to do both ends.

[gggplaya]

Yea, if it's just a 2WD, then you just need to do the rear axle which is much easier and cheaper since the front is more labor intensive. The rear is pretty easy, maybe an hour or 2 of labor cost and $200-300 for the ring and pinion set. Definitely well worth the upgrade if you plan on doing extensive towing.

[Lori Meyer]

Can't I just leave it as it is (3.55)?

[CJBROWN]

You really need to do some testing. Rent a trailer before you buy one. Try it out. Rent a couple of them at different sizes/weights. See how it does.

Do you need to climb mountain passes in your travels?

A lower differential gear ratio gives the drivetrain better leverage against the weight. Especially starting and for climbing grades.

[gggplaya]

A numerically higher ratio means the engine will spin so many times more per full revolution at the wheels. Overall it will shorten all of your gears to work within a smaller range. So each gear will climb less mph per gear but give you a better torque spread for pulling your load. The tachometer will climb much faster because the gear is shorter, the shifts will happen much faster, and keep you in your power band for overall much longer than a numerically lower gear ratio.

With a numerically lower gear ratio each gear will have a longer spread to climb. So lets say the same gear buys you 15mph in a numerically higher ratio, while a numerically lower ratio buys you 25mph. But you'll spend much more time out of the power band waiting for the tach to climb.

Having more gears like in the new 8 speed rams helps to alleviate this problem and keep you in the power band, as well as having a shorter spread between gear changes. So you can get away with a lower numerical final drive ratio when you have more gears.

Personally i would spend the money and switch it out if i were doing extensive traveling. The 3.92 axle was an option on the 2003 ram 1500, and may have been necessary to give you the max tow rating. But really like CJ brown said try it out. If you buy a trailer and the truck needs a little more help towing, then you could always pay to swap out the axle ratio later.

[Ray,IN]

Originally Posted by Lori Meyer

Can't I just leave it as it is (3.55)?

Yes you may. The truck might be a bit slower on steep hills, but will get you to the top, just don't floorboard it trying to go faster. On long steep grades you usually see truck lanes for slow moving vehicles, use it and be happy you are seeing our great country.

[onechaddude]

You might look in the glove box and see what axle ratio the truck has. I believe the 1500 trucks if it came stock with 20" wheels came standard with 3.92 ratio. That may also have only been with 4x4 also. Dodge used to list many of the options on a sticker located in the glove compartment. Can't verify any of these just remember some of these things over the years.
Chad

[caissiel]

My friend had a 95 2 x 4 Ram with 3.55 rear and toed a 7k trailer ok.
Then he bought a 10k unit thinking he was ok but he got in trouble in the hills. Everything overheated, engine transmission and I can bet the rearend to.

[gsmith31]

yes you can

[Lori Meyer]

Thanks for everyone's insight, very helpful.

The truck as the tow package with a transmission oil cooler and we're going to find an RV under 6,500 lbs. I believe it will handle that, plus we never go over 55 mph anyway (we're not in a hurry). :-)

[gggplaya]

Forgot also, does your truck have towing mirrors??

Something like these, which extend out.
2003-2008 Dodge Ram Extending Fold Towing Mirrors Power